Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-20T15:45:15Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Alexandre K. P. Souza.pdf: 3464696 bytes, checksum: e78461b89f866435b0635d96ae2a3f7d (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-20T15:45:30Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Alexandre K. P. Souza.pdf: 3464696 bytes, checksum: e78461b89f866435b0635d96ae2a3f7d (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-20T15:46:53Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Alexandre K. P. Souza.pdf: 3464696 bytes, checksum: e78461b89f866435b0635d96ae2a3f7d (MD5) / Made available in DSpace on 2017-02-20T15:46:53Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Alexandre K. P. Souza.pdf: 3464696 bytes, checksum: e78461b89f866435b0635d96ae2a3f7d (MD5) Previous issue date: 2016-12-16 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Electronic devices for applications in the field of electronic instrumentation in the offshoot of analytical chemistry research have great interest in the field of research related to the academic environment, as well as in the industrial environment. With the objective of extracting information and relevant data of chemical compounds, both from the qualitative point of view, as well as from the quantitative point of view, it is necessary in electrochemical analyzes, the presence of specific electrochemical sensors connected to electronic circuits, thus forming Electrochemical systems designed with the purpose of processing and extracting data information related to the physico-chemical effects occurring on the surface of the sensor due to reactions in the chemical substance or compound of interest in a particular analysis. This work deals with the research, study and development of topologies of electronic circuits, known as potentiostat, having as main objective, the task of conditioning of electrical signals from an electrochemical sensor, called electrochemical cell of three electrodes. The results demonstrated in this work are concentrated in the graphs of electrical voltages and currents, directly related to the chemical parameters of a sample under analysis, being these results obtained through experimental tests, applying the cyclic voltammetry method. Experimental tests were performed with circuit topologies connected to a cell, for the analysis of data obtained and validation of proposed potentiostat circuit topologies. / Dispositivos eletrônicos voltados para aplicações na área de instrumentação eletrônica no ramo de pesquisas em química analítica possuem grande interesse de desenvolvimento, nos campos de pesquisas relacionados ao meio acadêmico, assim como, no ambiente industrial. Com o objetivo de extrair informações e dados relevantes de compostos químicos, tanto do ponto de vista qualitativo, bem como do ponto de vista quantitativo, faz-se necessário em análises eletroquímicas, à presença de sensores eletroquímicos específicos conectados a circuitos eletrônicos, formando desta maneira sistemas eletroquímicos, projetados com a função de processar e extrair informações de dados relacionados aos efeitos físico-químicos, que ocorrem na superfície do sensor, devido a reações na substância ou composto químico de interesse em determinada análise. Este trabalho aborda a pesquisa, estudo e desenvolvimento de topologias de circuitos eletrônicos, conhecidos como potenciostato, tendo por tarefa o condicionamento de sinais elétricos provenientes de um sensor eletroquímico, designado de célula eletroquímica de três eletrodos. Os resultados demonstrados neste trabalho estão concentrados no levantamento de gráficos de sinais elétricos de tensões e correntes, relacionados diretamente a parâmetros químicos de uma amostra em análise, sendo estes resultados obtidos através de testes experimentais, aplicando o método de voltametria cíclica. Foram realizados testes experimentais com as topologias de circuitos conectados a uma célula, para a análise dos dados obtidos e validação das topologias de circuitos de potenciostatos propostos

In 1998, it was proved by Ben-David and Litman that a concept space has a sample compression scheme of size $d$ if and only if every finite subspace has a sample compression scheme of size $d$. In the compactness theorem, measurability of the hypotheses of the created sample compression scheme is not guaranteed; at the same time measurability of the hypotheses is a necessary condition for learnability. In this thesis we discuss when a sample compression scheme, created from compression schemes on finite subspaces via the compactness theorem, have measurable hypotheses. We show that if $X$ is a standard Borel space with a $d$-maximum and universally separable concept class $\m{C}$, then $(X,\CC)$ has a sample compression scheme of size $d$ with universally Borel measurable hypotheses. Additionally we introduce a new variant of compression scheme called a copy sample compression scheme.

In the Spring of 1998, the Virtual Corporation at Virginia Tech demonstrated the ability of Linear Switched Reluctance Propulsion (LSRP) to propel a vehicle on a track using only the interaction of a passive magnetic component carried on the vehicle with electromagnets built into the track. The Mark II project was a follow-on effort to complete a thorough design analysis of a second iteration vehicle which features the complete functionality of the original vehicle, with the addition of the ability to enter and exit the LSRP track system using remote control and an electric motor. The new vehicle also features certain design improvements in communications and structural rigidity. This paper elaborates on the process of design and analysis of the vehicle and ramp systems, including detail design drawings, finite element analysis of the vehicle chassis, powertrain subsystem analysis, and detailed analysis of the ramp surface contour design. / Master of Engineering

Vehicular Communication (VC) network technology is in the verge of real world deployment. The technology is aimed at achieving high levels of traffic efficiency security and comfort for the users of the traffic system. The technology facilitates exchange of awareness and notification messages among the vehicles to improve the traffic efficiency and safety of the drivers. However, deployment of this awesome technology faces several security and privacy risks. The system is subjected to security risks like replay attacks, nodes sending false information to the system, denial of service attacks by clogging the networks. System also faces several privacy challenges in which sensitive user data can be eavesdropped and also tracing out a particular node using the location data sent by the node. In this research we focused on protecting the privacy of the users using the VC system. Several European projects have been working on privacy enhancement techniques for VC environments. Privacy policy enforcement approach from Privacy Enabled Capability In Co-Operative Systems and Safety Applications (PRECIOSA), pseudonym approach from Secure Vehicular Communication (SeVeCom) and Preparing secure V2X Communication Systems (PRESERVE) project which integrates the results from both PRECIOSA and SeVeCom projects are three of those projects considered in this report. This research is more focused on the pseudonym approach proposed by SeVeCom. We discuss the impact of pseudonym change on the communication stack, what other lower layer identifiers need to be changed along with the pseudonym change, and is there any other ways the attacker can still link the messages from a particular node to hamper the nodes privacy. Finally after analyzing the results from the research, we propose a solution to include a new module in the PRESERVE architecture called Identifier Change Management (IDCM) module to improve the anonymity of the user participating in the vehicular communication.

This paper investigates the strategic framing approaches implemented by tech entrepreneurs in developing economies to attract financing from venture capital (VC) firms in developed economies. The study addresses the limited research in the field of entrepreneurship, specifically focusing on entrepreneurs’ subjective perspectives on strategically framing their startups to secure VC investment from developed economies. Additionally, it aims to make an initial contribution by exploring how these tech entrepreneurs in developing economies strategically frame their start-ups to attract VC funding from developed economies. The research methodology involves conducting semi-structured interviews with tech entrepreneurs who have successfully attracted VC financing through strategic framing.By analysing the interview data, we dive into the strategic framing approaches utilized by these tech entrepreneurs, with a particular emphasis on entrepreneurs in Kenya as the sample case, to secure financing from VC firms in developed economies. The insights shared by the interviewed tech founders highlight the crucial factors they strategically consider when framing their startups to attract VC financing. This strategic framing process involves extensive research, multiple iterations of pitch decks, metrics, and legal frameworks for a startup to raise VC financing. This study provides valuable insights into how entrepreneurs strive to understand venture capitalists’ perceptions of the Kenyan tech startup landscape and the criteria VC firms seek prior to making investments. Such knowledge empowers startup founders to position themselves strongly in terms of financial opportunities during the scaling and shaping phases of their tech startups. It is important to note that this study focuses on a small group of tech entrepreneurs in Kenya and may not capture potential industry, cultural, geographical, and personal variations. Nevertheless, it represents an initial attempt to explore the framing strategies of these startups when raising VC investments.

Ergospirometri används bland annat för att påvisa ansträngningsutlöst bronk- obstruktion. Tillståndet kännetecknas av ett fall i den forcerade exspiratoriska volymen på en sekund (FEV1) efter kraftig fysisk ansträngning. Den maximala sänkningen av FEV1 efter ansträngning anges i procent av FEV1 före ansträng- ning. FEV1 och vitalkapaciteten (VC) bestäms före och efter ansträngning med enkel spirometri. Själva provokationstestet utförs genom maximal belastning på ergometercykel. Före cyklingen utförs den enkla spirometrin med konventionellt munstycke och näsklämma. Vid provokationstestet används en tätslutande silikonmask av Hans-Rudolph serien 7450 vilken är avsedd för ergospirometri. Efter cyklingen får patienten behålla ergospirometrimasken på för att utföra mätningarna av VC och FEV1 i vila. Syftet med studien var att undersöka om det finns en skillnad i VC och FEV1 vid enkel spirometri utförd med ergospirometri- mask jämfört med enkel spirometri utförd med konventionellt munstycke och näsklämma. Alla mätningar utfördes i vila. Resultatet från Student's t-test påvisade statistisk signifikant skillnad för FEV1. Majoriteten av deltagarna uppvisade högre värden på FEV1 med ergospirometrimasken. För VC påvisades ingen statistisk signifikant skillnad. Därmed föreligger det en stor överens- stämmelse mellan munstycke och ergospirometrimask i mätningar av VC enligt Bland Altman Plot. Resultatet har visat att det föreligger skillnader mellan konventionellt munstycke och ergospirometrimask som kan vara av klinisk relevans. Det innebär att konventionellt munstycket och ergospirometrimask bör inte användas omväxlande vid provokationstestet. Vidare studier behövs göras för att kunna dra ytterligare slutsatser om huruvida andningsutrustningarna kan användas omväxlande. Ett fall i FEV1 efter ansträngningsprovokationen kan antingen bero på ansträngningsutlöstobstruktion eller att mätningarna som utförs före och efter belastningen är inte tillräckligt jämförbara.

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Cette thèse est principalement dédiée à la simulation des écoulements massivement décollés dans le domaine spatial. Nous avons restreint notre étude aux écoulements d'arrière-corps, pour lesquels ces décollements sont imposés par des changements brutaux de la géométrie. Dans le domaine spatial, le caractère fortement compressible des écoulements rencontrés impose l'utilisation de schémas numériques robustes. D'un autre coté, la simulation fine de la turbulence impose des schémas d'ordre élevé et peu dissipatifs. Ces deux spécifications, apparemment contradictoires, doivent pourtant coexister au sein d'une même simulation. Les modèles de turbulence ainsi que les schémas de discrétisation sont indissociables et leur couplage doit impérativement être considéré. Les schémas numériques doivent garder leur précision formelle dans des géométries complexes et des maillages très irréguliers imposés par le contexte industriel. Cette étude analyse le schéma de discrétisation utilisé dans le code de calcul FLUSEPA développé par Airbus Defence & Space. Ce schéma est robuste et précis pour des écoulements avec chocs et il présente une faible sensibilité au maillage (l'ordre 3 étant conservé même sur des maillages fortement perturbés). Malheureusement, le schéma possède une trop faible résolvabilité liée à un niveau de dissipation trop élevé pour envisager des simulations hybrides RANS/LES. Pour pallier à cet inconvénient, nous nous sommes penchés vers une solution basée sur un recentrage conditionnel et local : dans les zones dominées par des structures tourbillonnaires, une fonction analytique assure un recentrage local lorsque la stabilité numérique le permet. Cette condition de stabilité assure le couplage entre le schéma et le modèle. De cette manière, les viscosités laminaire et tourbillonnaire sont les seules à jouer un rôle dans les régions dominées par la vorticité et servent aussi à stabiliser le schéma numérique. Cette étude présente de plus une comparaison qualitative et quantitative de plusieurs modèles hybrides RANS/LES, à égalité de maillage et de schéma utilisés Pour cela, un certain nombre d'améliorations (notamment de leur capacité à résoudre les instabilités de Kelvin-Helmohlotz sans retard), proposées dans la littérature ou bien introduites dans cette thèse, sont prises en compte. Les applications numériques étudiées concernent des géométries allant de la marche descendante au lanceur spatial complet à échelle réduite. / This thesis is mainly dedicated to the simulation of massively separated flows in the space domain. We restricted our study to afterbody flows, where the separation is imposed by abrupt geometry changes. In the space domain, highly compressible flows require the use of robust numerical schemes. On the other hand, the simulation of turbulence imposes high-order low dissipative numerical schemes. These two specifications, apparently contradictory, must coexist within the same simulation. The coupling between turbulence models and discretization schemes is of the utmost importance and must be considered. Numerical schemes should keep their formal accuracy on complex geometries and on very irregular meshes imposed by the industrial context. In this research, we analyze the discretization scheme implemented in the FLUSEPA solver, developed by Airbus Defence & Space. Such a scheme is robust and accurate for flows with shocks and exhibits a low sensitivity to the grid (the third order of accuracy being ensured, even on highly irregular grids). Unfortunately, the scheme possesses a too low resolvability related to a too high numerical dissipation for RANS/LES simulations. To circumvent this problem, we considered a conditional and local re-centering strategy: in regions dominated by vortical structures, an analytic function provides local re-centering when a numerical stability condition is satisfied. This stability condition ensures the coupling between the numerical scheme and the model. In this way, only the turbulent and the laminar viscosities play a role in regions dominated by vorticity, and also allow to stabilize the numerical scheme. This study provides also a qualitative and quantitative assessment of several hybrid RANS/LES models, using the same grids and discretization scheme. For this purpose some recent improvements (improving their ability to trigger the Kelvin-Helmohlotz instabilities without delay), proposed in the litterature or suggested in this work, are taken into account. Numerical applications include geometrical configurations ranging from a backward facing step to realistic launcher configurations.

Bakgrund: Riskkapital är en betydande finansieringsmetod för unga företag. Riskkapital tillhandahålls av Venture Capital-bolag som har en betydande inverkan på det investerade företaget. Venture Capital-bolagens fokus under den period som de är investerade i portföljbolagen ligger på tillförsel av värde och övervakning. Trycket för företag att arbeta mer med hållbarhetsfrågor har ökat. Vilket öppnar frågan om hur de kan använda ESG för att öka värdet i sina portföljbolag. Mål: Syftet med denna studie är att ge förståelse för hur svenska Venture Capital-bolag arbetar med ESG som ett verktyg längs alla investeringsfaser för att kunna tillföra värde till sina portföljbolag. Metod: För att besvara frågeställningen samt uppnå syftet av studien har semistrukturerade intervjuer genomförts. Det har genomförts sex intervjuer där fem av respondenterna arbetade på ett Venture Capital-bolag och en respondent arbetade på en intresseorganisation. Resultaten av intervjuerna jämfördes med tidigare separerade resultat till ämnena ESG och Venture Capital. Slutsats: Betydelsen av ESG i portföljföretag kan variera på grund av bristande standard inom branschen. Några monetära värdeökningar har inte kunnat fastställas däremot är en del av respondenterna eniga om att ESG bidrar till värdeökning genom mjukavärden. Alla respondenter tror att ESG kommer ha en betydande roll i framtiden för branschen. Vidare har det kunnat observeras att respondenter tror på att ESG bidrar till riskminimering som enligt teorin tillför värde i bolag. / Background: Venture Capital is a significant financing method for young companies. Venture capital is provided by Venture Capital companies that have a significant impact on the invested company. The focus of the Venture Capital companies during the period in which they are invested in the portfolio companies is on the supply of value and supervision. The pressure for companies to work more with sustainability issues has increased. Which opens the question of how they can use ESG to increase the value of their portfolio companies.  Objective: The aim of this study is to provide understanding how Swedish Venture Capital are working with ESG as a toll along all investment phases to be able to add value to their portfolio companies.  Methodology: To answer the question and achieve the purpose of the study, semistructured interviews were conducted. Six interviews were conducted in which five of the respondents worked at a Venture Capital company and one respondent worked at an interest group. The results of the interviews were compared with previously separated results for the topics ESG and Venture Capital.  Conclusion: The importance of ESG in portfolio companies may vary due to lack of industry standards. No monetary value increases could be determined, however, some of the respondents agree that ESG contributes to value increases through soft values. All respondents believe that ESG will play a significant role in the future of the industry. Furthermore, it has been observed that respondents believe that ESG contributes to risk minimization, which according to the theory adds value in companies.

The diploma work deals with comparison of sintered carbides in product assortment of Pramet Tools a.s., Sandvik-Coromant and Ceratizit companies in term of their cutting speed, feed and depth of cut for the turning operation. The comparison of cutting parameters is made for P, M, K, N, S and H groups. For better comparison there are always two sintered carbides from each of the manufacturers mentioned for each of the groups P, M, K. They are mentioned for groups N, S and H only if they are suggested by the manufacturer.